The topical penta-peptide Gly-Pro-Ile-Gly-Ser increases the proportion of thick hair in Japanese men with androgenetic alopecia.

Background: A penta-peptide, Gly-Pro-Ile-Gly-Ser (GPIGS), promotes proliferation of mouse hair keratinocytes and accelerates hair growth in mice.

Aim Of This Study: This study focused on the ability of the peptide to promote human hair growth.

Methods: We used a human hair keratinocyte proliferation assay and organ cultures of human hair follicle as in vitro systems.